In recent years, a low-temperature fixable toner has been earnestly desired from the viewpoint of speeding up and miniaturizing an apparatus, and a combined use of a low-softening point amorphous resin and a crystalline resin (see Patent Publication 1), or the like has been studied.
On the other hand, when a copolymer in which a crystalline polyester and an amorphous vinyl resin which are mutually incompatible are chemically bound is used as a resin binder, the provision of a heat treatment step has been known to be effective in improving crystallinity (see Patent Publication 2 and Patent Publication 3).    Patent Publication 1: JP 2001-222138 A    Patent Publication 2: JP-A-Sho 64-35456    Patent Publication 3: JP-A-Hei 1-163757